THE Queen was given a private screening of War Horse yesterday after the Duke and Duchess of Cambridge sang the film’s praises.

Director Steven Spielberg flew in for the special showing at Windsor Castle, where one of the plush state rooms was transformed into a cinema.

A giant projector screen was set up in the vast wood-panelled Waterloo Chamber, with surround sound and seating for about 100 people in luxury ­upholstered armchairs.

William and Kate returned from the glittering premiere on the eve of the Duchess’s 30th birthday in January giving it rave reviews but, despite it coming out months ago, the Queen has been too busy to see it.

The royal “premiere” was ­arranged so household staff could also enjoy the movie, with its ­director on hand to answer any questions about what went on behind the scenes.

A royal source said: “The Queen loves horses and is a keen supporter of the military so it was only natural that she should want to watch War Horse.”

I was sitting next to her and all I know is at one point my wife, who was sitting to my right, right in front of my face she passed a Kleenex…

Director Steven Spielberg

The film, starring Benedict Cumberbatch (pictured above), Tom Hiddleston and Emily Watson is based on the children’s book by Michael Morpurgo about farmhand Albert, who tries to track down his beloved horse Joey after it is shipped away to serve in the First World War.

Acclaimed by critics, the film proved a hit at the box office, ­raking in £110million and was nominated for six Oscars and five Baftas.

Six hundred current and former members of the military and their families attended the star-studded premiere in London’s Leicester Square, where the royals’ co-star on the red carpet was the film’s equine lead, the chestnut colt that played Joey.

Afterwards the couple hosted a champagne reception at the Queen’s Gallery in Buckingham Palace for 100 selected guests ­including the director, cast ­members and wealthy donors who paid £10,000 each to attend. All proceeds went to the charitable foundation set up by Princes William and Harry, of which Kate is now also a patron.

Spielberg, 65, whose wife is the actress Kate Capshaw, later told how enthusiastic the royals had been about the movie and revealed how Kate’s tears had welled up during some of the scenes.

He said: “I was sitting next to her and all I know is at one point my wife, who was sitting to my right, right in front of my face she passed a Kleenex…

“I saw the Kleenex go across my face, arrive and stop but I didn’t want to intrude on her ­experience watching War Horse so I never glanced over. ­According to my peripheral vision her eyes were dabbed.”

Like the original 1982 book, the film focuses on the atrocious ­conditions horses were forced to endure during the Great War.

Between four and eight million perished on both sides and at times as many as 1,000 a day were arriving in France from Britain to replace those lost.

The Monarch is famously ­passionate about horses and has owned a number of thoroughbred racehorses.

Despite turning 86 next month, she still rides and last Easter was photographed with her grandchildren Lady Louise Windsor and James, Viscount Severn, during a hack through Windsor Great Park.